In modern printing operations it is desirable to print a maximum number of pages during each revolution of a press cylinder. Typically, this desire is satisfied by printing a signature which forms a section of multiple pages for a book. During a later binding operation the signature is folded with the end result being that the printed pages are in a proper orientation and position.
In order to print a signature, it is necessary that the printing plate include all of the pages in the proper orientation relative to one another. This process is known as imposition. Imposition has generally been done manually. A film comprising a scaled image of each page is manually positioned on a template for a particular signature printing to create a flat. The flat may be exposed, for example, on a photosensitive aluminum plate ultimately used for printing. The individual pages can be bottled or shingled as necessary.
The above-described manual imposition process requires that the operator initially choose the correct imposition template and then properly position the film for each page to create the flat. This is a time consuming process which adds inaccuracies to the system.
More recently, customers have used desktop publishing software to create the pages for documentation with all text, graphics, half-tone and spot colors in place. While this permitted the customer to proof the individual pages prior to printing, the manual imposition process remained.
Systems have further been automated by the ability to transmit customer page data to the printer who could then use a film printer for printing film for each page. Again, these pages were manually imposed.
It is desirable to provide an automated imposition system which is easy to interface with customer electronic publishing systems, provides output at desired quality expectations, is inexpensive and is useful with existing production capabilities.
The present invention is intended to overcome one or more of the problems discussed above.